Nine-year-old boy scrambles Anchorage airport security

Greg Warren, spokesman for the federal Transportation Security Administration, said the boy triggered the metal detector at the main checkpoint for Concourse B, then wandered off at about 10 a.m. Wednesday.

''And they couldn't find him,'' Warren said. ''He had gotten through and they didn't know where he was.''

It was unclear how the boy left unnoticed, he said.

Because airline officials didn't know how he had triggered the alarm, the concourse was no longer considered safe, Warren said.

That meant shutting the area down in accordance with standard policy of the Transportation Security Administration. The agency manages airport checkpoints, security procedures and staffing nationwide.

''When you close the concourse, you have everyone come out,'' Warren said. ''And they have to be screened and searched again in order to come back through.''

Officials soon found the boy as the crowd streamed out of the concourse on the airport's top level. Among the crowd were 122 passengers waiting to leave on Alaska Airlines Flight 98, the only flight delayed by the security breach, Warren said.

Some planes landed and sat idle on the runway. Larry Persily was aboard Alaska Airlines Flight 73 from Juneau.

''We sat on the tarmac for probably 25 or 30 minutes before they let us out,'' Persily said.

Beyond the concourse entrance, a ''horrendous mass'' of ''hundreds of people'' waited to clear the metal detector, Persily said.